1. Field of the Invention
The present invention relates to a process for the recovery of valuable monoalkylates from high boiling residue (flux oil) of aromatic alkylation processes, thereby improving the yield of monoalkylates in an aromatic alkylation process. More particularly the invention relates to a process for converting the heavier polyalkylates of the flux oil to monoalkylates and lighter polyalkylates.
2. Related Art
Aromatic alkylation processes are used to prepare various useful alkylated derivatives of benzene and naphthalene. For example, dodecylbenzene, a useful precursor for the surfactant industry may be prepared by the alkylation of benzene with dodecene in the presence of a suitable catalyst. Other examples include the alkylation of benzene with ethylene or propylene to yield ethylbenzene or cumene respectively. Ethylbenzene may be converted to styrene, and cumene is useful in the production of phenol and acetone.
In aromatic alkylation processes it is generally difficult to control the product distribution and one normally obtains an appreciable amount of polyalkylates. Since the products of the monoalkylation are more valuable, the di, tri, and tetra-alkylates may be separated from the monoalkylates and then transalkylated to produce more of the monoalkylate. See for examples, U.S. Pat. Nos. 5,055,627 and 5,243,115. The general practice has been to discard the heavier polyalkylates (flux oil) to fuel oil.
It is an advantage of the present invention to convert at least a portion of the heavier polyalkylates to lighter polyalkylates which can be more readily transalkylated to the monoalkylate.